The present invention relates to a method and apparatus for manufacturing cellular window coverings. More particularly, the invention relates to a multi-cellular window covering with a pleated face and a tabbed face.
There are several types of products in the field of cellular window blinds. These include single cell and multiple cell products. There are also pleated exterior surfaces and tabbed exterior surfaces and mixtures thereof. The materials used in different cellular shade products are likewise of a wide variety.
There are several methods used to make multiple cell products. One method utilizes a single sheet of material that is accordion folded to form a plurality of pleats. Each pleat is adhesively attached to an adjacent pleat at selected positions so as to make different products.
The single sheet and accordion fold method of producing cellular window shades begins with a sheet is shown in U.S. Pat. No. 5,702,552 to Kutchmarek et al. This patent discloses a method of making a pleated window covering using a single web of material, folded transversely to form pleats. Each pleat is adhesively attached to an adjacent pleat. This method results in a product with folds on both faces, and the width of the resultant product is limited by the size of the web of material.
The single sheet and accordion method is also illustrated in U.S. Pat. No. 5,630,898 to Judkins which discloses a method of making a final product that has folds on one face. In order to obtain the tab on side of the finished product and a fold on the other side of the finished product, an intermediate product with two pleated surfaces is created. This intermediate product has to be split in order to create the final fold and tab product. This method has the limitation discussed above, in that the width of the product is limited to the width of the sheet employed. Additionally, this method results in wasted materials, as a second cutting processing step is required and there is scrap left from the cut portion of the intermediate product.
Another method of making cellular products is to use a strip of material as the input. Using a strip of fabric rather than a sheet allows a wider variety of configurations to be made because the width of the final product is not limited to the width of the sheet material as it is with the single sheet method. With both the sheet method and the strip method of producing cellular products, both single and multi-celled products can be made.
U.S. Pat. No. 5,834,090 to Huang discloses a strip process in which individual strips of material are folded and attached together with an adhesive to create a cellular structure. As shown in FIGS. 7-13 of ""090 the referenced patent, the sheets are folded into a variety of configurations before adhesively attaching the sheets together. All of the configurations though result in a product with two pleated faces rather than a fold and tab appearance.
Thus there is a need and desire for an efficient method and apparatus for making a multiple cell window covering that does not use the accordion method of manufacture, and results in a product with a fold and tab appearance. It would also be desirable for a method and apparatus for making a multiple cell window covering that does not require a longitudinal cut at an intermediate stage of the product manufacturing process in order to make the final product.
One method of making a double cell window shade includes providing a length of material, folding the length in half to form a fold, two free ends, a top half, and a bottom half, one of the halves having an outer surface. The top half is then attached to the bottom half along a line located greater than half the distance from the fold to the free ends. A first adhesive is applied to the outer surface along a line located less than half the distance from the fold to the free ends. A second adhesive is applied to the outer surface along a line proximate the free ends. The length of material is cut into individual strips and stacked such that the lines of adhesive of each strip make contact with the adjacent individual strip.
Another embodiment of the method of making a double cell window shade includes providing strips of material, folding each strip longitudinally to form a fold, two free ends, a top half, and a bottom half, one of the halves having an outer surface. The top half of each strip is attached to the bottom half of the same strip along a line two-thirds of the distance from the fold to the free ends. A first adhesive is applied to the outer surface of each strip along a line one-third of the distance from the fold to the free ends. A second adhesive is applied to the outer surface of each strip along a line proximate the free end. The strips are stacked such that the adhesives of each strip make contact with the next overlying strip.
A method of making a triple cell window shade includes providing a length of material, folding the length longitudinally to form a fold, two free ends, a top half and a bottom half, one of the halves having an outer surface. The top half is attached to the bottom half along a first longitudinal line between the fold and the free ends, and along a second longitudinal line proximate the free ends. A first adhesive is applied to the outer surface along a line closer to the fold than the first longitudinal line, and a second adhesive is applied to the outer surface along a line between the longitudinal line and the first adhesive. The length of material is cut into individual strips that are stacked.
A method of making a multi-cell honeycomb product includes providing a length of material, folding the length longitudinally to form folded material, the folded material having a fold, two free ends, a top half, and a bottom half, one of the halves having an outer surface. The folded material is divided into a plurality of longitudinal segments, one through N, the first segment beginning at the fold, the Nth segment ending at the free ends. The top half is attached to the bottom half along lines located in selected segments and adhesive lines are applied to the outer surface along lines located in other segments. The folded material is cut into a plurality of individual strips of material, and those individual strips are stacked.
An apparatus for manufacturing a multi-cell fold and tab honeycomb product includes a folder, an ultrasonic welder receiving the output of the folder, an adhesive applicator receiving the output of the ultrasonic welder, a stacker for stacking the output of the adhesive applicator, and an oven for baking the contents of the stacker. The product has a folded face and a tabbed face.